This invention relates generally to gas turbine engines and, more particularly, to assembling rotating components of gas turbine engines.
At least some known gas turbine engines include a core engine having, in serial flow arrangement, a fan assembly and a high pressure compressor which compress airflow entering the engine. A combustor ignites a fuel-air mixture which is then channeled through a turbine nozzle assembly towards low and high pressure turbines which each include a plurality of rotor blades that extract rotational energy from airflow exiting the combustor. Gas turbines are used in different operating environments, such as, to provide propulsion for aircraft and/or to produce power in both land-based and sea-borne power systems.
During normal operation gas turbine engines may experience high rotational speeds. An imbalance of the rotor may cause vibration of the rotor and induce stresses to rotor bearings and support structures. Over time, continued operation with such stresses may lead to failure of the bearings, bearing support structure, and/or rotor components. Failure of a component within the engine system may damage the system and/or other components within the system, and may require system operations be suspended while the failed component is replaced or repaired. More particularly, when the component is a turbofan gas turbine engine fan blade, a blade-out condition may cause damage to a blade that is downstream from the released blade.
At least some known turbofan gas turbine engines include a fan base having a plurality of fan blades extending radially outwardly therefrom. To facilitate minimizing imbalance of the fan during operation, known fan assemblies are assembled in a controlled manner. For example, one control that may be used in assembling fan rotors is mapping each blade of the fan into specific slots in the fan base. Within other known fan assemblies a moment weight of each blade is determined and the determined moment weight is used to map each blade into specific fan base slots. However, because the geometry of adjacent blades may be different, during operation a rotor may still experience a shift in balance that is not associated with the moment weight of each blade.